Just upgraded: Hiface EVO!

[kamil]

I guess I must be one of the first to get this from M2Tech, so here is a quick and dirty review. I understand samples are few and far between for end users and this must be a pre production run model.

 

1) As a current standard Hiface user, I was not disappointed with the improvement using same coax cable, but with standard computer USB cable. Powered by a cheap wall wart. First thing to strike me was the cleaner treble.

 

2) Add a 9v alkaline battery and it takes on another level. No opportunity to compare to Jkenny's mod but generally better imaging, more 3d, and extended bass.

 

3) The killer for me was when I tried it via ST optical on a friend's W adia. Now if you have a copy of Sony Rollins, Way out West, first track: I'm an Old Cow Hand, you will know what I mean. This is available on vinyl too but the vinyl always invariably sounds better than digital. The digital can sound slow and boring.... But through the ST; wow! The last time I heard it sound this good was through the Continuum Caliburn super turntable...from the timing of the drums to the rasp of the saxophone, the new Evo via optical has me rethinking my vinyl collection.

 

Qualifier: I have only had a short time with this and there are too many inputs and output, power supply options to explore, but like the original Hiface, this must be one of the best value upgrades i have made in a while.

 

[ferenc]

I got an EVO to try as well, it works like charm. Even with cheap wall wart. I tried it with a Paul Hynes power supply as well (made for my Altmann DAC earlier), it is much more sophisticated of course, but even with the 10 Euro wall wart ps it something very special. I am using the RCA coax (Acrolink digital cable) and BNC coax output (Naim DC-1 BNC-BNC coax cable) to a Naim DAC with XPS2 power supply and it is very difficult to think of anything better for the price to be honest. Later I will try it with an external clock generator and the special laboratory purpose USB hub, the Vaunix as well. I have the very same feeling about the improvements as Kamil had.

 

[barrows]

For the preliminary reviews. Kamil, Way Out West has been one of my references for awhile now-one thing to listen for is how Sonny Rollins moves around the microphone-sometimes turning towards his bandmates to cue them. Also the fullness and nice round tone of the bass drum. This must have been a very simply miked recording, and the session was in the early morning hours which probably avoided mains contamination. Great quality recording, regardless (or perhaps because of...) its age.

 

[lennmax]

I should receive one next week. if it proves to be equal or even better than the modded one I'm gonna be so so so very pleased. looking forward to more impressions...

 

[kamil]

One other thing that strikes me on the Evo is the improvement on the midrange and voices, which I have not really experienced on previous jitter reducing upgrades. soaring vocals are just that more real and dynamic with less tonal break up.

 

Granted, few have it, but including ST optical is sheer genius as it really isolates the computer RFI from the rest of the system.

 

This purchase really makes me wonder why others have to charge ( and I bought them!) so much on exotic digital cables and mods. Even out of the box, there are so many cheap upgrade options to play around with. That's what makes this fun. Kudos to M2Tech for another game changing product.

 

[lennmax]

I have a couple of questions:

 

"Add a 9v alkaline battery and it takes on another level."

 

does the EVO have an internal space for a 9v battery? and was it both powered by the wall wart & the 9v battery at the same time, or was it by just the 9v battery that took it to another level.

 

also could explain what the ST optical is? can you recommend a good one? I was going to exclusively use my precious digital cable with it, but I'm curious about this ST now.

thanks

 

[kamil]

Lennmax, about the battery, no there is no space for any battery inside. The EVO has an external socket for a power source, be it battery or adapter. You need to buy the right plug and wire it to the battery.

 

Alternatively, the wall wart that came with the unit had a connector to charge a 9V battery, so i just disconnected the mains power and fitted an alkaline battery which in turn feeds the EVO through the same cable that connects to the EVO's socket.

 

As for ST optical, this is an optical connection which is only compatible with a DAC that has an ST (AT&T) standard input. Some EMM Labs & Wadia dacs have this and so does the upcoming Vaughan DAC from M2Tech. If your DAC doesn't have it, you might have to buy one with this input in order to use this connection.

 

[jkeny]

Can I ask what is the advantage of ST optical over Toslink? I never came across ST optical before - is it lower jitter or why is it included?

 

Edit: I eventually found some info on it here: http://en.wikipedia.org/wiki/Optical_fiber_connector

 

So it looks like just a different mechanical end connector? I don't really understand why it was included as it's not a common connector or is it? Is there some advantage that I'm missing?

 

[Paul R]

They have been around since Moby Dick was a minnow, but most shops today use LC connections for things like networks and fibre channel SANs. Or one of several other variants. AT&T used this connection on their early fibre voice networks.

 

Paul

 

 

[blueixus]

As already mentioned Wadia used to offer this option between Transport and Wadia Dac.

 

It was very much their preferred connection route, remembering back to my Wadia owning days it worked very well, in fact much better than SPIDF.

 

I didn't know why then and I still don't today so hopefully someone can shine a light of this seemingly mostly forgotten technology...

 

[jkeny]

Hehe, I'm as old as Moby Dick but I never heard him spout anything about ST connectors - always learning . Is their sonic advantage to them?

 

Edit: I crossed post with blueixus, - so there seems to be a sonic advantage? I doubt it's just down to the ST connectors however so somebody might be able to say if there are different Tx & RX chips or doe sthis operate at AES/Bu signal levels & not at SPDIF signal levels. Always learning

 

[kamil]

Here is a good writeup on ST Optical and Toslink

 

http://www.audioholics.com/education/cables/toslink-interconnect-history-basics

 

[jkeny]

I also found this piece from here: http://www.stereophile.com/cdplayers/189/index10.html

 

These are glass guys. Off-the-shelf integrated glass optical transmitters combine the driver circuitry and laser transmitter into one unit. But according to Wadia, such transmitters are intended for use in long-distance telecommunications; when used in short audio lengths, they overload the receiver and cause jitter. So Wadia designed a discrete glass optical transmitter tuned for shorter lengths which, they claim, lowers jitter. They say the improvement can be heard in any D/A converter with a glass-fiber input.

 

Which seems to indicate that Wadia used proprietary optical transmitters!

 

[kamil]

Genesis168 over at Audiogon sums it up like this (bandwidth for toslink has since gone up to 10mhz):

 

http://forum.audiogon.com/cgi-bin/fr.pl?fcabl&1019742769&openfrom&7&4#7

 

"Firstly, bandwith of TOSLINK is only 6 MHz. ST glass optical is between 50-150 MHz and electrical coax is 500 MHz.

 

I am not saying that the transmitter is sending the signal too fast. Rather when receiving the signal and CONVERTING it to electrical signal has a back log in doing so (takes time to do so). Transmitting will be at light speed. Receiving too at light speed but the conversion to electrical is where the problem is. Jitter is the timing error for this..we're talking micro secs to miliseconds

 

AT&T ST optical has far wider bandwidth therefore will better handle the signal at the receiving/conversion side."

 

[Paul R]

Leaving out Wadia specific issues, "SPIDF" is a protocol, meaning you can transmit it over media you like - copper, fibre, radio, etc. The connectors have nothing to do with the format of the transmission.

 

It's not really "forgotten" technology so much as out of date; you can still find it used here and there, usually by the quantity and volume of the curses of the engineer that finds it.

 

However, the quality of a cable with ST connectors on it is likely to be much higher than your typical TOSLink cable, and the connectors themselves are built to much higher tolerances.

 

That's because they were originally used in voice networks - and at a time when we did not know how to manufacture high quality connections cheaply.

 

I expect that using a cable with ST connectors might provide better sound, but then, I do not know. Typically TOSLink optical drivers use a very low power LED to transmit the signal, not a laser. The maximum transmission length is very limited with a light source like that.

 

-Paul

 

 

[jkeny]

Genesis168 seems to me to be so wrong that I don't know where to start. Does he not realise that the transmitter determines the speed of the signal?? Where does the higher bandwidth come from, the connectors? His explanation of jitter is hilarious!

 

Thanks Paul, so it might be that the fibre cable & connectors form a better connection? But isn't the issue with Toslink that the transmitters & receivers introduce excessive jitter? Are we talking about proprietary optical transmitter/receiver chips as per Wadia, to get any advantage or are there sepcific ST chips??

 

[juanitox]

hi , the avantage is the glass fiber but also hte mechanical connection .. a cable guy working at french telecommunication company told me that they put some transparent "gel" at the end of the fiber to get a perfect contact with the connector.

 

( sorry for my english, i'm french)

 

[Paul R]

In general (i.e. not specific to high end audio!) Optical data links are rather immune to jitter. Meaning they can tolerate high levels of jitter with no impact on the data or sound quality, in regards to a voice network.

 

Modest lengths are usually meant to be less than 100 klicks, and the tolerable error rate is somewhere around 1 error in 10 followed by 15 zeros. Optical links transmit data reliably.

 

When you are talking the minute distances we use in our systems, the equation really changes, and I have not worked out the math. Maybe I will give that shot, at least roughly, over the weekend.

 

But purely my opinion, the proprietary Tx/Rx integrated devices in a Wadia are far more responsible for any sound improvement than the cable or connectors. Not that the cable and connectors might not contribute to improved sound, but I think the proprietary chips' contribution would very much overshadow anything else.

 

Just my $0.02. YMMV, etc.

 

 

-Paul

 

 

 

 

[kamil]

Here is the link to the document referred to by M2Tech describing the ST Optical transmitter.

 

http://www.avagotech.com/docs/AV02-0723EN

 

[kamil]

This is the inside of my Evo. Looks like alot more has gone into it apart from just more inputs and outputs.

 

[jkeny]

Yes, Kamil, thanks for publishing this pic - very interesting. That looks like a Spartan Xilinx chip - what markings on it?

It seems to have 3 Regulators - what are the markings on them?

 

[PeterSt]

It would be nice to know (for me / XX) what's on that larger long shaped chip near the bottom of the picture. I think that is memory, and before people run into all kind of playback problems, it is good to know the (max) buffer size.

 

If you don't want to tell it, no problem.

Peter

 

[lennmax]

kamil, what are your impressions/memory so far of the EVO's compared to the standard HiFace... would you say it's an improvement in SQ alone?

 

I don't need the extra connectors, and would get the EVO solely for its performance - otherwise I'll stick with the HiFace.

 

[kamil]

Peter, what looks like a memory chip is a CY7C68013A USB microcontroller from Cypress.

 

John, sorry, have to check again the next time I open it up. The music is just soooh good.

 

[The Computer Audiophile]

Here is a detailed PDF about the Cypress EZ-USB CY7C68013A microcontroller.

 

http://www.cypress.com/?docID=21813